In Sheet2, cell N2, I want to calculate the maximum value:

MAX(sheet1!B8,sheet1!F8,sheet1!J8,etc,

Ive already been shown (by some very learned and helpful fellows on this
site - thanks) that in cell E2 of Sheet2 the SUM of these cells can be
obtained using

=SUMPRODUCT(--(MOD(COLUMN(sheet1!8:8)+2,4)=2), sheet1!8:8)

but dont know how to perform the MAX function in a similar manner. Or even
if this is the best way.

Furthermore, I dont follow the relationship between the cell Im in and the
cells Im trying to SUM, MAX, etc, and the figures +2 and =2 (in the
example). The concept of COLUMN(sheet1!8:8) -

Can anyone help? Thanks for help already received in this area. It is
highly appreciated. Keep up the good work!